Unusually sensitive people:Consider reducing prolonged or heavy outdoor exertion. Watch for symptoms such as coughing or shortness of breath. These are signs to take it a little easier.

Everyone else: It’s a good day to be active outside.

Unhealthy for Sensitive Groups
(101-150)

Sensitive groups include people with lung disease such as asthma, older adults, children and teenagers, and people who are active outdoors.

Sensitive groups:Reduce prolonged or heavy outdoor exertion. Take more breaks, do less intense activities. Watch for symptoms such as coughing or shortness of breath. Schedule outdoor activities in the morning when ozone is lower.

People with asthma should follow their asthma action plans and keep quick relief medicine handy.

Note: If you don't have an air conditioner, staying inside with the windows closed may be dangerous in extremely hot weather. In these cases, seek alternative shelter.

Key Facts to Know About Ozone:

Ozone in the air we breathe can cause serious health problems, including breathing difficulty, asthma attacks, lung damage, and early death.

Ozone forms in the sun, usually on hot summer days. Ozone is worse in the afternoon and early evening, so plan outdoor activities for the morning.

You can reduce your exposure to ozone and still get exercise! Use the Air Quality Index (AQI) at www.airnow.gov to plan your activity.

What is ozone?

Ozone is a colorless gas that can be good or bad, depending on where it is. Ozone in the stratosphere is good because it shields the earth from the sun’s ultraviolet rays. Ozone at ground level, where we breathe, is bad because it can harm human health.

Ozone forms when two types of pollutants (VOCs and NOx) react in sunlight. These pollutants come from sources such as vehicles, industries, power plants, and products such as solvents and paints.

Why is ozone a problem?

Ozone can cause a number of health problems, including coughing, breathing difficulty, and lung damage. Exposure to ozone can make the lungs more susceptible to infection, aggravate lung diseases, increase the frequency of asthma attacks, and increase the risk of early death from heart or lung disease.

Do I need to be concerned?

Even healthy adults can experience ozone’s harmful effects, but some people may be at greater risk. They include:

People with lung disease such as asthma

Children, including teenagers, because their lungs are still developing and they breathe more air per pound of body weight than adults